Lightning can strike twice!

A couple of years ago, a lightning bolt struck our neighbors grand oak tree and killed it. The massive crack, flash of white light and static electricity in the air was incredible. Our house is about 30 yards from the tree. We all thanked our lucky stars that the lightning strike did not hit any of the houses. However we quickly found out that lightning causes electro-static discharge (like a kind of EMP) and spreads charge through the air and ground in quite a large radius. This surge is carried by any good conductor which in our case was all our coaxial, CAT 5e ethernet, HDMI and electric cables. As a result we lost our modem, outside projector, two flat screen TV's, three mac mini media servers, network switch, alarm system, a mac air, toaster, fridge freezer (compressor), AC compressor and many other smaller things. The crazy thing was that some things did not fail immediately but went days or sometimes weeks later or became unpredictable. It was not only the cost, but the inconvenience of doing without and replacing everything. 

We now live with far more technology than ever before and are extremely vulnerable to lightning strikes and electric surges from an unstable grid. It doesn't even have to strike your house directly, but just be close by as we found out. Many devices have sensitive connections to wires like HDMI, coax and ethernet cables that get fried easily. We also live in a lightning prone state in the USA and so I went on a mission to find out what we could do to protect ourselves. If your house gets struck directly there is not much you can do to protect everything against a billion volts, but there are cost effective ways to isolate and protect your expensive devices. 

Step 1 - protection against the big stuff

The first step we did was to install "whole house" power surge protection devices on all the main electricity panels i.e. outside your house, in the garage, pool equipment sub-panel. Also install protectors on the air conditioner compressors. These guard against the big surges of 40,000 amps+ before they even get into the house. A licensed electrician is required to do this work and you should also get them to test and make sure the house ground wiring and earth prong is installed correctly. Make sure the devices you use have thermal fuses and have lights or alarms that notify you that you have been hit. Note that these devices typically stop 80% of the surge meaning 20% will still leak into your house. This is where a second more sensitive surge protector at 200+ amps should be installed on your house appliance panel usually installed in the garage. This will stop the majority of the surge and trip in a nanosecond. Even so, some surge (approx. 10%) will still leak through and this is where special plugs, power strips and UPS (uninterruptible power supply) devices come in.

Step 2 - protecting power outlets inside the home

These devices are "plug in" specialized for individual appliances, the familiar power strips for general use and UPS power cleansing and battery backup units. These effectively provide a buffer between the wall outlets and appliances/devices containing sensitive electronics e.g. motherboards. We started by installing the specialized individual appliance plugs on our refrigerators, freezer, dishwasher, washing machine, AC units. Basically anything with a motor or a higher than normal draw. These plugs are single phase supporting a configurable under and over voltage e.g. 90-140 volts with a typical working current of 20A. When they are tripped, they automatically reconnect after a period of time e.g. 3 minutes.

Next we installed UPS (uninterruptible power supply) devices in our home office, entertainment system and kids gaming areas. These units typically come in various sizes to support different voltage capacities. We selected two 1500va for our larger home office/computer center, three 1000va units for our entertainment system areas and two 500va units for the kids gaming computers. For you guys who don't know, a UPS "cleans" the current, has a battery to continue power for a small amount of time and provides multiple outlets to all your devices. It acts as a buffer between the wall outlet stopping any surges and power problems. All our modem, router, network switches, NAS devices, printers, TV's, AV's, computers, laptops, media servers plug into these. The UPS status can also be automatically monitored by USB connection or over the network. This is handy for computers, servers, NAS devices to gracefully detect an outage and gracefully shut themselves down. Well worth configuring.

Lastly, we placed a surge protection power strips in each room. These also have USB charger outlets for phones, tablets, speakers. Note that not all power strips are created equal. Make sure the ones you get have a built-in 10A circuit breaker for overload protection, indicator lights for power on normal mode and USB charging, on/off switch, at least 175 Joules surge protection and is made of fire retardant materials.

Step 3 - Protecting your Coax Ethernet and HDMI cables

In our house we have a cable modem, a fixed Ethernet CAT 5e network and HDMI cables linking our devices throughout our house. We found out the hard way that all these cables are great conductors of electric surges that will easily fry sensitive electronic equipment. Many of these cables also go through walls and roof spaces. There are low cost in-line connectors that can provide a further line of protection. These are usually installed as close to the device as possible using a short jumper cable and have a ground wire that is connected to the nearest plug outlet ground. They typically work using a "gas discharge tube" that diverts excessive current to ground. We also found that we should use at least AGW 14 ground wire. Again beware of cheap devices and it is worth doing the research and paying a bit more. We purchased eight HDMI power protectors for our TV's, AV's and projector, two coax RG6 for our cable modem and TV arial, and five RJ45 CAT 5e/6a Ethernet 4 port power surge protectors for our entertainment systems and home office network.

The second strike ... and not out      

We live in a lightning prone area in the southern USA and installing power protection is definitely a great idea. The first time we lost $15-20K of appliances and devices. The total cost of installing all the power protection above including labor came to a bit over $4K. The second time we got struck, 8 months later, it hit a power pole across the street and a tree right next to the house. A double whammy! The main house surge protectors we installed all tripped as well as nine of the appliance protector plugs and strips. We had to replace just six of the gas discharge tubes and five GFI plugs at a cost of $290.

Our neighbor on the other hand had to replace most of his house wiring and plugs, lost most of his electrical devices and had to call the fire brigade. I am still surprised at how many people are not protected since 1 in 200 houses get struck by lightning in the USA every two years. We have since worked with all our neighbors and HOA to do what we have done.

Useful links:  

  • More information on surge protection, click here
  • Download the free surge protection PDF.
  • To shop for surge protection devices and solutions, click here.

Leave a comment

Please note, comments must be approved before they are published